Jet.com
Obviously a supplier to NASA and the rest of the photographic world. I especially love how they call it a 650-2600 but their description calls it a 650-1300 lens.
Specifications Zoom Type: Push/Pull (Two-touch) Focus Modes:
Manual Focus Minimum Focus Distance: 16'(4.9 m)
Angle of View: 3.8 to 2 Degrees
Aperture: f/8-16
Filter Size: 95mm Max Diameter: 4.1"(105mm) Length: 18.5"(23.3" at full zoom) Weight: 4.4 lb (2 kg)
Included Items~ Opteka High Definition 650-1300mm Super Telephoto Zoom Lens ~ Opteka High Definition 2X Teleconverter ~ T-Mount Lens Adapter ~ Lens Hood ~ Padded Pouch with Shoulder Strap ~ Front and Rear Lens Caps
Save the $185.00 and add it to other savings and get a good zoom. The 150-500 is popular for both it's quality and it price.
150-500mm F5-6.3 APO DG OS HSM | Sigma Corporation of America